bug#13649: boobytrapped dired-do-async-shell-command question

[Drew Adams]

> > Apologies for not following this.
> > If you're looking for a key that will show some help,
> > maybe consider `?'.
> 
> How can we use a printable character in yes-or-no-p, 
> which expects the user to type readable text?  

Apologies, I was thinking of y-or-n-p.

(I use it only where a single char is read.)